Hydrometallurgy of copper.



E. R.WE|DLEIN HYDROMETALLURGY OF COPPER.

APPLICATION man vAuexsmsls.

Tan lrls Fil fer Maffe/,2,215 ran/r Patented oet. 17,1916.`

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l'arl To Wei y -Tan K5 A "Hof Leach So/u/'on E. a. WEIDLEIN. HYYDROMETALLURGY or COPPER. l APPLICATION FILEQ AUGIS. 191-5. 1,201,899. Patented 0ct.17,1916.

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EDWARD RAY WEIDLEIN, CF TH0MPSON,INEVADA, ASSIGN OR TO'METALS RESEARCH COMPANY, .OF NEW YORK, N. Y., A CORPORATION 0F MAINE.

HYDROMETALLURGY OF COPPER.

Specification of Letters Patent.

Patented Oct. 17, 1916.

Application filed August 31, 1915. Serial No. 48,150.

To all Hwm. it may conccrn.'

Be it known that I. Eiiwxnnlhr 7mo- Linx, a citizen of the United States, residing at Thompson. county of Lyon, State of Nevada, have invented certain new and useful Improvements in IIydroinetallui-gy of Copper; and I do hereby declare the following to be a full, clear. and exact description of the invention. such as will enable others skilled in the art to which it appertains to make .and use the same.

This invention relates to the recovery of copper in a wet way, from its ores.

In my prior Iatent No. 1,089,006. granted March 3, 1914-, I have described and claimed the extraction of copper from copper bearing material by means of sulfuric acid and the precipitation of the copper from the resulting copper sulfate solution by treatment with sulfur dioxid at a suitable temperature and pressure.' This precipitation of c opper isbased generally upon the reversible reaction leaclied with a 3.6% sulfuiic acid solution,

and'a leach solution is the free acid is then neutralized, andthe copper sulfate solution containing about 1.5% coppei` is mixed with an approximately equal amount -of sulfur dioxid .and then heated in the precipitating Vtank or tanks to a temperature of about 150o C. and a pressure of. inch. Under these conditions the copper is precipitated substantially quantitatively produced suitable for re-leaching purposes.

'In said prior patent it was proposed to leach with the solution as it comes hot from the precipitation tanks, thereby utilizing its maximum leaching efficiency, and making the process continuous in the sense that the leaching solution is utilized over` and over again for re-leachiiig the ore, after the cop-v per has been precipitated each time out of the solution. I ha'ye now found that the process can be carried on more advantageously by making it continuous in the sense that the solution is continuously passing through the precipitating tank or tanks and is continuously heated therein, thereby precipitating the copper andregenerating the sulfuric acid. I have furtherfound it to about 100 pounds per square-F rom this heat interchanger` -the solution, instead of leaching the ore directly with this hot solution. As a result of this heat interchange the copper sulfate solution is preheated and the precipitating i'eaction is thereby facilitated, while the cooling of the hot leach solution makes it also more etticient iii that the acid losses arc materially reduced by the use otl a cooler leaching or` extracting acid.

I will now proceed to describe -my invention iiiore'iii detail. with particular refei= ence to the apparatus illustrated. more or less diagrammatic, upon the iu-coiiipairving drawings, but it is intended and understood thatthe invention will be illustrated by, but is not limited to, the specific vembodiments thus illustrated and described.

In the accompanying drawings, Figure 1 shows a diagrammatic arrangement ot' apparatus in which the novel process of the invention can be practised. and Fig. shows. partly in section. and partly in elevation. the recipro ating and heat imei-changing parts of the apparatus.

Referring tirst to Fig. 2. the storage tank for the copper sulfate solution, after ha ving been neutralized and charged with sulfur dioxid, is indicated at 1 and is provided with an outlet 2, having therein a regulating valve 3, leading to the heat intel-changer of any suitable or preferred construction. solution passes through the pipe 5 to the pump 6. by means of which it is forced into the precipitating tank 9 under a suitable pressure of. for example, 100 pounds per square inch. The pipe leading from the pump 6 to the precipitating tank is provided with an outer oil jacket 7, and has an upwardly arranged discharge end S within the tank. From the top of this tank the solution or liquor is withdrawn by means of the pipe 10. pro vided with a suitable regulating valve 1l, and is returned thereby to the heat interchanger 4, from which it is in turn forced through the )ipes 12 and 1l by means of the pump 13 bac to the leach tanks.

The precipitating tank or chamber 9 is suitably supported upon supports 15 and is provided With an outer double wall or other suitable means for heating by means 0f oil. Such oil heating I have foundto be particularly 'suitable Ifor l necessary temperature within -the'prec1p1tat1ng tank.

The oil heater is illustrated at 16,. provided the oilpasses meansiof V part through f-t e "branrslrfl with suitable air and fgasinlets" 17 and with a-funnel orchiinney-v 18,1-,- From the heater. arme l19, 1n'

, wall of the`precipitatinggtank,'an inpart laf 25, and -the ficircu' Anoil expansion ank 28isarranged` above vably Tconrieetefl the top 'of the ory systeinand is suit ,reto by of pipes 26'and 27.' n

The 'precipitatinggl-tank,isfproyldedi with liquid gages' 30""or'deterininingthe level thermometers T33 are also 'the temperature;

of theliquidtherein iid 'with openings 31 for i the, introduc' "on fthermoineters. It is1 also' providedi valve and-with thermometer 33. Similar r ous points o'theQappara s for'indicating The` ap"'aratusgofFig.j2,' corresponds tothe heat interchang'erffand precipitating `tower'of the diagramlof Fig. 1. Fromthe heat interchanger the'cool'ed leach solution' is returnedv to a suitable storage .tank or tanksl from'whichfitis drawn, as required, Iinto the lachQtanks'. The ore or other copperbearingl material is 'introduced into theleach ,tanks and there leached with the f'cooled sulfuric 'acid leachf'solution. TheQex# ,cess acid istli'en'iieutralized bythe addition of calcium carbonate rorfo'rdinarylimestone,`` -5 and the; precipitated gypsum-.is suitably re,-l

m'oved by sipliOning, lilteringor otherwise;

' .or the exces'slacid vcan beneutralizedby the use `ofumyf other suitable alkalinesubstancfe. r i This 'copper sulfate' solution should,jintheA preferred practice of. the inyentiom contain about 1.5% of copper. Sulfur dioitid forced into the copper lsulfat'esol l isinsiiin `suitablefamount, and the solution tor plays a Very small A'part in the reversible lreactionwhich results -infthis precipitation, y

and that justas'soon .as theJ proper condireached (.100 pounds pressure and 150 the reaction ris complete.

Gf), The prec1p1tat1on "of the copper 1s accompanied bythe regeneration of twice as much sulfuric acid as' responding amount of copper. `liquor thus produced is led off through the lol" the precipitating-tank By thus cooling the leach liquor before utilizing it for extracting further amounts of i ore, the -acid losses 1n the hotlsoluti'on can be materially reduced.v Thus, lit is possible to cool the.

outgoing solution from about 150O C. or 160 C. down to about 90 G., and at the theoretically required for extracting a cor'- .The leach 1 pipe 10 to the heat interchanger where it sulfate solu;v

temperature.

same time raise the temperature of the ii1v I Inasniuch as the precipitation reaction lresults 1n the production of twice as much HZSO, as is theoretically necessary Avto eX- tract a corresponding amount of copper partutilized for Sonie other purpose than eaching the ore, as will be readily understood. 4There may, however, be some loss goingv solution from about 20 C. to'ab'out 90. o.

from the ore, the excess acid may be in 70 tions of temperature. `and pressure are 'of acid during the eXtra-ctiong'in ,dissolving iron' or other constituents, and there will usually' lbe some lexcess of acid'to be neutrahzedafter, the leaching of the ore, so that v for the leaching operation.

10 a greateror less excesslof acid is desirable It will be seen'that the precipitation is cari ried on -in a continuous manner, the preheated copper sulfate Asolutiointogether with torn of the precipitating tank in a continuous manner,- and being continuously withdrawn at'thetop'afterthe precipitation of the copper therefrom; .I The 'precipitating stored in vsuitable storage'tan u f tank-ormtower is of suitablewheight, and which is'i-ndicated in FigpQ, from`.w ich the`vl shou'ld'lfy'y-Aith advantage. have such a height istv solution is drawn olii andipassedY Vto hot leach liquor coming from-the e precipitating tower, in -V tlie' manner" already indicated, The pre-heatedv copper sulfate solution. is forced under ia's'uitable pressure,

and inaJ continuous manner-,into -'the bottomj of the l precipitatingtankt) t ough the loil e jacket pipe 7,l in V`which it i'isfjffurtleefpre' heated. During lthe'Ypageage' up, through the precipitating tank the: coppersulfate=slu tion mixed with the sulfur dioxid is` heated to the necessary temperatureof about 15.0

fliehen? interchanger4, where i t` is preh'eatI op, 'ovfflh asfwllpermifthe heating therein of the 4the Isulfurdioxid, bemg'forcedl into thebotco per`'su1fate solutiontogether with the ,i2-0

I rom the bottom ofthe precipitating tank-.1T

the copper can be withdrawn, Without in.

pprovi'ded with a suitable outlet 3G.

rlhe constantrpressure can be maintained within the precipitating tank by suitable regulation of the pump G and by means of the safety valve 32 set at a pressure of. 100

pounds. Y The temperature can ,be regulated by the automatic recording gages or thermometers, and by the regulation of the -oil heater. It will be seen that the heated oil is'circulated int-o heat inter-changing relation with the liquid Within the precipitating tank; and that in the particular apparatus illustrated, this circulation is effected through thesurrounding jacket of the precipitating tank and of the inlet pipe 7. Gther suitable or equivalentl methods of effecting the necessary heat interchange between the oil and the liquid Within the precipitating tank' will operate in a -similar manner. l

lith a tank such as illustrated, of about three feet in diameter and 20 feet high, hay@ ing a capacity of about 1000 gallons of solu-` tion, it is possible to handle from 50,000 to 100,000 gallons of solution during 24 hours, the circulationof the solution and the operation of the process being effected in a con tinuous mannen, such as above described, and substantially complete precipitation' of the copper being obtained.

From the foregoing descriptionv it Will be seen that the process is a continuous one in the sense that the circulation of the reacting solution through the precipitating apparatus is effected in a continuous manner with resulting continuous precipitation of the copper therefrom. It Will also be seen that the resulting hot leach liquor is cooled before extraction of the ore therefrom and that the copper sulfate solution is itself thereby preheated, With the result that the copper sulfate solution enters the precipitating tank already partly heated to the precipitating temperature, and the leach liquor enters the leaching tank sufficiently cooled to prevent objectionable loss of the a'cid. YVhile the conditions of the reaction indicated are `sure to eiect precipitation ofthe copper `and form a residual leach liquor of relatively llow percentage in copper as compared With its original copper content, drawing olf such leach liquor ina continuous manner, and circulating the same and the ingoing solu-` tion in heat interchanging relation/With each other, andA thereby cooling the hot leach liquor 'and preheating the ingoing solution; substantially as described.

2. The method of extracting copper from ores, roasted matte, and other copper bearing material, which comprises leaching the Amaterial with sulfuric acid to obtain "a suitable copper sulfate solution, heating such solution with sulfur dioxid to asuitable temperature and pressure to effect precipichanging relation with each other, and` thereby cooling the hot leach liquor and preheating the copper sulfate solution, and

utilizing the cooled leach liquor to extract a p further portion of copper from the ore or other material treated; substantially as described.

3. The method of extracting copper from ores, roasted matte, and other copper bearing material, which comprises leaching the .material with sulfuric acid to obtain a suitable copper sulfate solution, circulating such solution, together with the sulfur dioxid, in a continuous manner through a precipitating apparatus, and heating the samel therein to a suiiicient temperature and pressure to effect precipitation of the copper and forni a residual leach liquor of relatively low percentage in copper as compared with its original copper content, drawing oif such leach liquor in a continuous manner, and circulating the same and the ingoing solution in heat interchanging relation with each other, and thereby cooling the hot leach liquor and preheating the ingoingsolution,

utilizing the cooled leach liquor to extract aV further portion of copper from the ore or other material treated, neutralizing' the excess acid in the resulting copper sulfate solution, and continuing the process by circulatliov ing the neutralized solution in heat interchanging relation with further amounts of.,

hot leach liquor, and thereby preheating the same, and thence through the precipitating apparatus in the manner indicated; sub stantially as described. K

4C. The method, of precipitating copper from copper sulfate-solutions by means of sulfur dioxid, Which comprises circulating -suchr solution, together with the sulfur dioxid, in continuous manner upwardly through a precipitating tank of considerable `height and lheating the saine in its passage upwardly therethrough to a sufficient temperature and pressure to effect preclpitation 4of the copper and form a residual leach liquor, of relatively low percentage in cop- -per as compared with its original' copper content, collecting and drawing 0H the copper from the bottomof the precipitating tank, and continuously drawing oli' the leach liquor substantially free from precipitated copper from the top of the precipitating tank; substantially as described.

5. The method ofv extracting copper from ores, roasted matte, and other copper bearing material, which comprises 'leaching the material with sulfuric ac1d and obtaining a copper sulfate solution of a strength not substantially exceeding 1.5% metallic copper, neutralizing the free sulfuric acid contained in the solution, -circulating the solution, together with sulfur dioxid, in a con tinuous manner through a precipitating al,

paratus and heating the same therein to a copper content, drawing off such leach liquor in a continuous manner, and circulating the same and the ingoing solution in heat interchangingl relation with each other,

and thereby cooling the hot leach liquor and preheating the ingoing solution, utilizing the thus cooled leach liquor to'extract a vfurther portion of copperfrom the ore or other material treated, and continuing'the process in the manner indicated; substantially as described. i

In testimony whereof I affix my signature. 40

EDWARD RAY WEIDLEIN.

Gopies ofthis patent may be obtained for ve cents each, by addressing the Commissioner af-Patenti,

` Washington, D. c.

in copper as compared with its originalv 

